Electrostatic flocking apparatus



Aug. 30, 1966 w. J. FRIDERICI ELECTROSTATIC FLOCKING APPARATUS Filed Aug. 22, 1963 United States Patent O 3,269,356 ELECTROSTATIC FLOCKING APPARATUS Wayne I. Friderici, Port Clinton, Ohio, assignor to The Standard IProducts Company, Cleveland, Ohio, a corporation of Ohio Filed Aug. 22, 1963, Ser. No. 303,777 l Claims. (Cl. 118-640) This invention relates to new and novel flocking apparatus especially designed to effect electrostatic flocking of fabric fibers and the like and more particularly .to flocking apparatus for providing a uniformly distributed electrostatic field for the purpose of electrostatically depositing elongated fibrous particles onto adhesive covered surfaces to effect a flocked article of substantially high uniform density.

Heretofore, one of the major probelms encountered in electrostatic flocking has been the developement of an electrostatic field whereby fibers deposited in said field are substantially uniformly distributed so that upon deposition thereof lonto the base material a uniform density of said flocking material is accomplished.

In the apparatus of t-he present invention, a substantially uniform electrostatic field is provided by means of a novel and unique electrode assembly whereby a uniform cloudlike distribution of flock fibers is Iaccomplished which distribution may be of any predetermined volumetric configuration as is determined by the configuration of the respective electrodes of said assembly.

It is therefore a primary object of the present invention to provide a novel electrostatic flocking apparatus that is capable of providing a substantially uniform electrostatic flocking field into which an article to be flocked may be presented, whereby as a result of said field, a substantially uniform deposition of fibers may be applied to the flocking surfaces of said article.

Another object of the present invention is the provision of an electrostatic flocking apparatus wherein a novel electrode assembly is effective to generate a substantially uniform electrostatic flocking field and wherein at least one electrode of said assembly is mechanically vibrated so `as to prevent the flock particles from piling up onto the electrode as a result of gravity and/or electrostatic attraction.

Still another object of the present invention is the provision of an electrode assembly for use in an electrostatic flocking apparatus, and which electrode assembly partakes of such configuration as to effect a substantially uniform electrostatic field and hence a uniform distribution of flock fibers in said field.

Another object of the present invention is to provide an electrode assembly especially designed for use in an electrostaic flocking apparatus and which electr-ode assembly is intended to be located in close relationship with an article presented thereto such that the electrostatic field and distribution of flocking material therein is confined within a predetermined area that is closely adjacent said article.

Additional objects and .advantages of the electrostatic flocking apparatus of the present invention will be apparent to one skilled in the art to which it pertains and upon reference to the following disclosure of a preferred embodiment thereof and which is illustrated in the accompanying drawings wherein:

FIG. 1 is a view in side elevation of electrostatic flocking apparatus embodying the present invention;

FIG. 2 is a transverse sectional view taken approximately on the plane as is indicated by the line 2-2 in FIG. 1; and

FIG. 3 is a perspective view of the upper electrode assembly incorporated into said apparatus.

With reference now directed to the drawings, the flock- 3,269,356 Patented August 30, 1966 ICC ing apparatus herein disclosed -is seen to include a boxlike housing 10 mounted von legs 11, the interior of said housing defining a flocking chamber 13.

Upper and lower electrode assemblies 15 and 16 respectively, are disposed in said chamber in vertical spaced relation to each other, said assemblies each extending longitudinally through said chamber preferably in parallel spaced relation, whereas a suitable source of electrical energy is applied thereto so as to generate an electrostatic field therebetween.

A conveyor as identified at 20 is disposed in the flocking chamber and preferably slides over and upon the lower electrode assembly 16, said conveyor supporting the articles C' to be flocked as t-he same are passed through said electrostatic field. As will be understood, the surfaces of the articles C to. which flock is to Ibe applied are usually treated with a suitable adhesive capable of ladhesively binding said flock fiber thereto.

The top wall 10a of the housing 1li is formed with an inlet opening 18 which communicates with a suitable flock supply 19 and through which flock fibers may be introduced into the housing. The upper portion of the housing as indicated at 21, forms a hopper which houses la rotating brush 22 or other suitable dispensing device for dispensing the ook fibers in a steady stream through a discharge opening 23 located in the base of said hopper whereby the fibers fall gravitationally in-to the aforesaid chamber 13.

A screen as indicated at 24 is located below the discharge opening 23 being suspended by and between spaced .flexible members 30 Vand is preferably vibrated so as to ena-ble the flock fibers to be distributed somewhat evenly `as they fall toward the upper electrode assembly 15.

As the fibers fall through said chamber and into the electrostatic field generated between the electrode -assemblies 15 and 16, they thence disperse through said field and are deposited onto the intended surfaces of the articles or base material passing therethrough.

As heretofore mentioned, the electrode assembly of the present invention is intended to 'generate a substantially uniform electrostatic field so that, as the flocking fibers are uniformly distributed throughout the same the deposition thereof onto the base material will be of relatively high uniform density.

To accomplish this the upper electrode assembly 15 is seen to include `a framework which comprises a pair of rail members 25 and 26 formed of a suitable nonconductive material such as wood, and which are arranged in an elevated position in said chamber above the conveyor 20, said rails extending longitudinally therethrough in predetermined parallel spaced relation to each other.

Each rail member is preferably disposed Iin an upright position and suspended in said chamber by means of a plurality of transverse support bars 29 extending across said chamber at preselected spaced intervals, said bars likewise being formed of a suitable nonconductive material.

As seen in FIG. 2, each support bar 29 is preferably suspended from the underside of the hopper 21 by the aforesaid flexible members 30 so .as to hang freely in said chamber 13.

A conventional mechanical vibrator 35 mounted on one of the side walls 10b of the housing and lying against bracket 36 carried on one of said support bars 29, is -operable to reciprocally vibrate the upper electrode framework transversely of the chamber 13 or in the direction of the arrow A in FIG. 2.

In like manner, a second vibrator 37 mounted on the underside of the hopper 21 engages bracket 37a carried on one of said bars 29 and is intended to cause a reciprocal vibration of the upper electrode framework longi- 3 tudinally of the chamber 13 in the direction of the arrow C in FIG. 1.

In actual use it may be desired to operate either or both the vibrators 35 and 37 so as to reciprocate the upper electrode framework accordingly.

The screen 24, being suspended between flexible members 30 is also vibrated -with the electrode assembly.

With this assembly, the flock fibers are prevented from falling onto and piling up on the top of the upper electrode Iassembly by reason of gravity and/ or electrostatic attraction which fibers, would gradually build up and fall into the flocking chamber as a dense mass to result in -uneven fiber deposition onto the base material.

As best seen in FIGS. 1 and 3, a plurality of electrode elements are carried on the laforesaid framework, each being identical in configuration and identified by the reference numeral 38.

Each electrode element is formed of a length of suitable conductive material such as copper wire bent into U-shaped configuration to form a pair of electrode branch arms 38a.

The rail members 25 and 26 are each formed on the underside surface thereof 'with a plurality of notches 41, 42 respectively, which are equally spaced therealong, the notches in each rail member being preferably spaced opposite the notches on the other rail member to thus form spaced notch pairs.

Each electrode arm 38a is inserted into one of said spaced pairs of notches in the rail members 25, 26 so as to extend transversely across the lframework in substantial parallel spaced relation to the next adjacent electrode arm on either side thereof. The free ends of each U- shaped element, as indicated at 39h, extends upwardly and along the outer side of the rail member 26 and is securely fastened at 40 to a conductive bus bar 42 carried on said rail member.

The opposite closed end of each electrode element extends upwardly along the outer side of rail member 25 and is fastened at 44 to one end of a coil spring 46, the opposite end of the latter being suitably fastened to anchor plate 47.

With this construction said electrode arms 38a are disposed in equal spaced relation longitudinally of the framework and extend substantially transversely between the rail members 25, 26 thereof.

Conductor 51 -as seen in FIG. 1 is connected to the bus bar 42 and extends outwardly through one of the housing side walls b from which it is suitably insulated as at 53, the opposite end of said conductor being connected to a suitable source of electrical energy such as rfor example an alternating 60 cycle current supply of approximately 50,000 Ivolts whereby said potential is applied to each of said electrode arms 38a.

With the framework vibrated longitudinally and/or transversely of the electrode 'arms 38a, the electrostatic field generated between the aforesaid electrode assemblies is substantially uniformly distributed within the flocking chamber.

The lower electrode assembly .16 is seen to comprise a bridge-like member 61 being formed of a suitable conductive material such as aluminum, and which pre'ferably is cast in one piece to form a flat rectangular central span 62 integrally formed on the sides thereof with upright legs 63.

The bridge member 61 is mounted on a nonconductive base 65 upwardly of the base 10d of the housing 10 -and extends longitudinally through the chamber 13 in such manner that the conveyor passes over and rests upon the -upper surface of the central span Ithereof as it moves through said chamber.

The bridge member 61 is likewise connected to the aforementioned electrical energy source so as to be of the opposite polarity rat any one instant with respect to the upper electrode assembly 15.

If desired, the bridge member 61 may be grounded so as to prevent the possibility of arcing when processing conductive parts.

As alternating electrical energy is applied to the upper and lower electrode assemblies 15 and 16 and with the upper assembly vibrating in the chamber 13 in the manner above described, an electrostatic field is generated there-between which has a volumetric configuration characterized by the approximate configuration of said electrode assemblies.

As the flock fibers are introduced into this electrostatic eld they become longitudinally aligned with the lines of force extending between said electrode assemblies and begin to move first in one direction toward either electrode assembly under the influence of said field and then in the opposite direction toward 'the'other of said electrode assemblies as the field polarity is reversed.

The distance the fibers move in'either direction increases progressively the longer they remain in the field and eventually are propelled sufficiently downwardly endwise into the adhesive surface of the articles C being carried on the aforesaid conveyor 20 to thus form a uniformly flocked surface.

It has been found that the electrostatic field has a tendency to be of a somewhat higher density alongside and outwardly of the sides of the conveyor 20 whereby the flock fibers are-bled from the areas closely adjacent said conveyor sides and drawn into said side areas. In this manner, the deposition of the flock fibers onto the base material is not uniform particularly in said adjacent areas.

To prevent this from occurring and to enable the full width of the conveyor 20 to be used, a strip of nonconductive material, as indicated at 75, is disposed along each side of the central span 62 of the bridge member 61 and rests upon a plurality of longitudinally spaced shelf members 70 formed integrally with said bridge member and projecting transversely outwardly therefrom. The shelf member 70 are disposed so as to locate the top surface of the strip 75 at approximately the same level aspthe adjoining surface of the central span 62 so as to provide a substantially continuous supporting surface to the aforesaid conveyor 20.

As seen in FIG. 2, each strip 75 is likewise preferably of such width as to exten-d laterally outwardly of the adjacent side of the conveyor 20 being thus interposed in the electrostatic field.

With this assembly, each strip 75, acts to yreduce the intensity of said field at said side areas and as a result of its insulating properties, the flock Idistribution in the area of the field closely a-djacent the sides of the conveyor is maintained substantially uniform. In this manner, the base material as is indicated at C', may be placed along substantially the full width of the conveyor and uniformly flocked. v

Having thus described in detail Ia preferred embodiment of electrostatic flocking apparatus, it will be apparent that the same is susceptible to various modifications, combinations and arrangements of parts without departing from the inventive concepts thereof yas are defined in the claims.

What is claimed is:

1. In flocking apparatus for electrostatically depositing fibers upon an article surface to form a pile layer thereon including a housing defining a flocking chamber, means for conveying an article to be flocked along a conveyance path through said chamber, means for introducing flock fibers into said chamber, a stationary electrode assembly disposed in said chamber at a first level and connected to a source of electrical energy, a movable electrode assembly disposed in said chamber at a second level above said stationary electrode assembly and comprising a pair of spaced rails of nonconductive material extending longitudinally along said path, a plurality of electrodes carried on said rails and extending therebetween and across said path in substantial equal spaced relation to each other, means connecting said electrodes in circuit with said source effective to provide an electrostatic field between said electrode assemblies, and means for vibrating the electrodes on said movable assembly transversely of said path effective to cause a substantial uniform distribution of flock liber throughout said electrostatic field.

2. In flocking apparatus for electrostatically depositing fibers upon an article surface to form a pile layer thereon including a housing defining a flocking chamber, spaced electrode assemblies in said chamber being connected to a source of electrical energy effective to generate an electrostatio field therebetween, means for introducing flock fibers into said chamber, means for conveying an article to be flocked along a conveyance path through said chamber between said electrode assemblies, one of said electrode assemblies having a central span underlying and positioned to provide support for said conveying |means, means adjoining the longitudinal side edges of said central span being operable to confine the flocking effects of said electrostatic field to said span, the other of said electrode lassemblies comprisin-g a pair of spaced rails of nonconductive material extending longitudinally along said path, a plurality of electrodes carried on said rails and extending therebetween and across said path in parallel-spaced relation to each other, and means for vibrating the electrodes on said movable assembly transversely of v said path effective to cause a substantial uniform distribution of flock fiber throughout said electrostatic field.

3. In flocking apparatus for electrostatically depositing fibers upon an article surface to form a pile layer thereon, a housing defining a flocking chamber, vertically spaced, horizontally disposed, upper and lower elongated electrode assemblies disposed within said chamber and connected to a source of electrical energy effective to generate an electrostatic eld therebetween, means movably mounting said upper assembly and means fixedly mounting said lower assembly within said housing, means for introducing flock fibers into said chamber above said upper electrode assembly, a conveyor disposed upon said lower electrode assembly parallel therewith for moving articles to be flocked along a path between said electrode assemblies, said upper electrode assembly comprising a pair of laterally spaced, parallel side rails of nonconductive material and a plurality of transversely directed, wire electrode elements, said electrode elements being uniformly spaced longitudinally along said upper electrode assembly, `means for vibrating said upper electrode assembly longitudinally and for vibrating said upper electrode assembly transversely to prevent the piling up of flock on said electrode elements, said lower electrode assembly comprising an elongated, flat support portion made of conductive material having a flat upper surface for receiving and supporting said conveyor.

4. In flocking apparatus as set forth in claim 3; said electrode elements formed in integral pairs, each pair comprising a single length of generally U-shaped wire having -two parallel branch arms extending between said rails with the terminals of each said pair being disposed adjacent to one of said rails.

5. In flocking apparatus for electrostatically depositing fibers upon an article surface to form a pile layer thereon, a housing defining a flocking chamber, vertically spaced, horizontally disposed, upper and lower elongated electrode assemblies disposed within said chamber and connected to a source of electrical energy effective to generate an electrostatic field therebetween, means movably mounting said upper assembly and means fixedly mounting said lower assembly within said housing, means for introducing flock fibers into said chamber above said upper electrode assembly, a conveyor disposed upon said lower electrode assembly parallel therewith for moving articles to be flocked along a path between said electrode assemblies, said upper electrode assembly comprising a pair of laterally spaced, parallel side rails of nonconductive .rnaterial and a plurality of transversely directed, wire electrode elements, said electrode elements being uniformly spaced longitudinally along said upper electrode assembly, means for vibrating said upper electrode assembly longitudinally and transversely to prevent the piling up of flock on said electrode elements, said lower electrode assembly comprising an elongated, flat support portion made of conductive material having a flat upper surface for receiving and supporting said conveyor, and elongated, fiat strips of nonconductive material mounted edgewise along the lateral edges of said support portion with their upper surfaces disposed coplanar with the flat upper surface of said support, said strips effecting a reduction in the intensity of said field along the side edges of said support whereby said flock distribution in the area closely adjacent to the sides of said conveyor is maintained substantially uniform.

References Cited by the Examiner UNITED STATES PATENTS 2,152,077 3/1939 Meston et al 118-624 X 2,173,032 9/1939 Wintermute 117-17 2,194,253 3/1940 Benner et al 118-638 2,428,991 10/1947 Ransburg 117-93.4 2,526,763 10/1950 Miller 117-93.4 2,715,585 8/1955 Schwartz et al. 117-17 2,811,134 10/1957 Friderici 117-17 X 2,976,839 3/1961 Okma et al 118-640 CHARLES A. WILLMUTH, Primary Examiner.

WILLIAM D. MARTIN, Examiner.

PETER FELDMAN, Assistant Examiner. 

1. IN FLOCKING APPARATUS FOR ELECTROSTATICALLY DEPOSITING FIBERS UPON AN ARTICLE SURFACE TO FORM A PILE LAYER THEREON INCLUDING A HOUSING DEFINING A FLOCKING CHAMBER, MEANS FOR CONVEYING AN ARTICLE TO BE FLOCKED ALONG A CONVEYANCE PATH THROUGH SAID CHAMBER, MEANS FOR INTRODUCING FLOCK FIBERS INTO SAID CHAMBER, A STATIONARY ELECTRODE ASSEMBLY DISPOSED IN SAID CHAMBER AT A FIRST LEVEL AND CONNECTED TO A SOURCE OF ELECTRICAL ENERGY, A MOVABLE ELECTRODE ASSEMBLY DISPOSED IN SAID CHAMBER AT A SECOND LEVEL ABOVE SAID STATIONARY ELECTRODE ASSEMBLY AND COMPRISING A PAIR OF SPACED RAILS OF NONCONDUCTIVE MATERIAL 